uaa2068g NXP Semiconductors, uaa2068g Datasheet - Page 2

• Manufacturer Part Number: uaa2068g
• Description: Transmit Chain And Synthesizer With Integrated Vco For Dect
• Manufacturer: NXP Semiconductors

Philips Semiconductors
FEATURES
APPLICATIONS
GENERAL DESCRIPTION
The UAA2068G BiCMOS device integrates a 950 MHz
VCO, a frequency doubler, main and reference dividers
and a phase comparator, to implement a phase-locked
loop for DECT channel frequencies. The 1.9 GHz signal is
buffered and switched, in TX mode, to drive the transmit
power amplifier (CGY20xx series) or, in RX mode, to be
used as an LO signal for the receiver mixer IC (UAA2078).
The synthesizer’s main divider is driven by the frequency
doubler output in the range from 1880 to 1920 MHz and
programmed via a 3-wire serial bus.
ORDERING INFORMATION
1998 Nov 19
UAA2068G
TYPE NUMBER
Economical integrated solution for frequency generation
in DECT cordless telephones
Integrated low phase noise 950 MHz VCO with
frequency doubler
Local Oscillator (LO) drive ( 14 dBm) for RF mixer
circuit
Dedicated DECT PLL synthesizer
3-line serial interface bus
3 dBm output preamplifier with an integrated switch
Low current consumption from 3 V supply
Compatible with Philips Semiconductors ABC baseband
chip (PCD509x series).
1880 to 1920 MHz DECT cordless telephones.
Transmit chain and synthesizer with
integrated VCO for DECT
LQFP32
NAME
plastic low profile quad flat package; 32 leads; body 5
2
The reference divider ratio is fixed at 8. Outputs of the
main and reference dividers drive a phase comparator
where a charge pump produces phase error current pulses
for integration in an external loop filter. Only a passive loop
filter is necessary. The charge-pump current (phase
comparator gain) is set by an external resistor at pin R
The VCO is powered from an internally regulated voltage
source and includes internal varicap diodes. Its tuning
range is wider than the required band to allow for
production spreads. In a TDMA system such as DECT, the
VCO and the synthesizer are switched on one slot before
the required one to lock the VCO to the required channel
frequency. Just before the required slot, the synthesizer is
switched off, allowing open-loop modulation of the VCO
during transmission. When opening the loop, the
frequency pulling (due to switching off the synthesizer) can
be maintained within the DECT specification.
The device is designed to operate from 3 NiCd cells in
pocket phones, with low current and nominal 3.6 V
supplies. Separate power and ground pins are provided to
the different parts of the circuit. The ground leads should
be short-circuited externally to prevent large currents
flowing across the die and thus causing damage.
All supply pins (V
except V
other supply pins (e.g. V
wider VCO control voltage range).
DESCRIPTION
PACKAGE
CC(CP)
which can be equal to or greater than the
CC
) must also be at the same potential,
CC
= 3 V and V
5
1.4 mm
Product specification
UAA2068G
CC(CP)
SOT401-1
VERSION
= 5 V for
SET
.